Spring wind-up mechanism

ABSTRACT

A mechanism is described for winding spring-driven toys. A clutch arrangement is employed wherein a driven clutch member of the toy spring drive is positively engaged by a driving clutch member of the wind-up mechanism. The clutch members are provided with teeth which engage in a positive and vertically retaining manner. The clutch arrangement provides a quickly engageable and releasable spring wind-up connection which is particularly useful as a fast &#39;&#39;&#39;&#39;pit stop&#39;&#39;&#39;&#39; with top vehicle racing games and with toy vehicle launchers. A vehicle launcher utilizing the wind-up clutch is described, wherein a pivotally mounted platform is inclined to convert it from a spring wind-up support surface to a toy vehicle launch ramp.

United States Patent [191 Ensmann et al.

[ May 29,1973

[ SPRING WIND-UP MECHANISM [75] Inventors: Burt Ensmann, Flushing; Edwin Nielsen, Oceanside, both of N.Y.

[73] Assignee: Ideal Toy Corporation, Hollis, N.Y.

[22] Filed: Mar. 22, 1971 [21] Appl. No.: 126,817

[52] US. Cl. ..46/202 [51] Int. Cl. ..A63h 11/10 [58] Field of Search ..46/202, 1 K, 39;

[56] References Cited UNITED STATES PATENTS Horn ..46/39 Lennont 185/39 FOREIGN PATENTS OR APPLICATIONS 1,905,263 3/1970 Germany ..46/l K Primary Examiner-Louis G. Mancene Assistant Examiner-J. Q. Lever Attorney-Richard M. Rabkin [5 7] ABSTRACT A mechanism is described for winding spring-driven toys. A clutch arrangement is employed wherein a driven clutch member of the toy spring drive is positively engaged by a driving clutch member of the wind-up mechanism. The clutch members are provided with teeth which engage in a positive and vertically retaining manner. The clutch arrangement provides a quickly engageable and releasable spring windup connection which is particularly useful as a fast pit stop" with top vehicle racing games and with toy vehicle launchers. A vehicle launcher utilizing the wind-up clutch is described, wherein a pivotally mounted platform is inclined to convert it from a spring wind-up support surface to a toy vehicle launch ramp.

16 Claims, 8 Drawing Figures PATENTED M91913 3,735,526

SHEET 1 [1F 3 1 SPRING WIND-UP MECHANISM FIELD OF THE INVENTION This invention relates to a spring wind-up device for use with toys. It particularly concerns a clutch mechanism for winding up spring-driven vehicles.

BACKGROUND AND SUMMARY OF THE INVENTION Spring drives for toys are well known, and have been used for many years. Conventionally, the springs of such toys are wound up on an output drum whichis rotated with a key that fits onto a coaxial extension of the output drum.

In a spring wind-up device in accordance with this invention, however, winding is accomplished by means of an engageable and releasable clutch. A wind-up clutch driven member is mounted on the spring drive of the toy. The driven member rotates about an axis and is op-' eratively coupled to the output drum for wind-up of a drive spring. A wind-up mechanism is provided, and supports a driving clutch member with is rotated by an actuator and engages the driven clutch member to wind the toy drive spring. Both clutch members are provided with extending teeth located at axial ends of the clutch members for axial engagement with the teeth of the other clutch member. The teeth are coaxially distributed about the axis of rotation of the clutch members, and surfaces of the teeth are slanted to form complementary re-entrant recesses sized to received the ex tending teeth of the other clutch member. When the toy and the wind-up mechanism are engaged, the teeth of the clutch members are thus interlocked to enable the wind-up mechanism to wind the spring on the output drum.

An advantageous feature of the wind-up mechanism of this invention resides in its quick engagement and release capability. This feature is particularly useful in connection with a toy vehicle race game or a toy vehicle launch apparatus in accordance with this invention. In such vehicle launch apparatus the wind-up mechanism is located on a housing carrying a pivotally mounted platform that may be transformed into an inclined ramp when pivoted and seated upon a vehicle running surface. The toy vehicle rests on the platform to-engage a driving clutch member mounted on the launcher. Upon completion of the wing-up of the spring in the toy vehicle, the platform is pivoted downward both to release the clutch members and to enable the vehicle to race off the ramp onto the running surface.

BRIEF DESCRIPTION OF DRAWINGS FIG. I is a perspective view of a wind-up mechanism in accordance with the invention, shown in conjunction with a vehicle spring drive, and with parts broken away to show constructional details.

FIG. 2 is an enlarged perspective view of clutch members employed in'accordance with the invention.

FIG. 3 is a top plan view of a toy vehicle wind-up and launch apparatus in accordance with the invention.

FIG. 4 is a side elevation view of the toy vehicle windup and launch apparatus of FIG. 3, with parts broken away and sectioned.

FIG. 5 is anend elevation view of the toy vehicle wind-up and launch apparatus of FIG. 3.

FIG. 6 is a section view of the toy vehicle wind-up and launch apparatus of FIG. 3 with the platform shown pivoted to a vehicle launching position.

FIG. 7 is a top plan view of an alternate wind-up mechanism in accordance with the invention.

FIG. 8 is a partial section view of the wind-up mechanism in FIG. 7, taken along the line 8-8 thereof, looking in the direction of the arrows.

DETAILED DESCRIPTION THE PREFERRED EMBODIMENTS With reference to FIGS. 1 and 2 a spring wind-up mechanism 10 is shown in conjunction with the spring drive 12 for a toy vehicle 11 (partially illustrated in FIG. 1). The spring drive 12 is supported on a vehicle frame 13 and includes a spring 14, for example of the Negator type, which is normally wound on a take-up drum l6 and attached to a rotatable output drum 18 by a bolt 20. The output drum 18 is mounted on a shaft 22 which is connected through a gear train 24 to drive axle 26 of the vehicle, whose rear wheels 27 only are shown.

The output drum 18 is provided with a driven clutch hub 28 which extends axially downwardly from the output drum for engagement with a driving clutch hub 30 of wind-up mechanism 10. Both the driven clutch hub 28 and the driving clutch hub 30 are provided with axially extending, co-axially distributed teeth 34 34' respectively which are slanted circumferentially and raked at re-entrant angles to form recesses 36 36. When presented to each other as seen in FIG. 2, the teeth 34 34' are oriented in opposite angular directions so that upon engagement the teeth of each clutch hub fit within the recesses of the opposite clutch hub for positive drive of output drum 18. The hubs 28 and 30 are molded of a plastic material such as high impact polystyrene, but the recesses 36 36' are bounded by re-entrant surfaces 37 preferably cut along radial lines by a cutting tool to form angles alpha of about 53. Note that if one of the hubs 28 or 30 were reversed relative to FIG. 2, the teeth 34 34 would extend in the same angular direction; thus, for ease of manufacture, a single set-up of the cutting tool can do all the re entrant surfaces 37 of both hubs.

The wind-up mechanism 10 includes a housing 38 which rotatably supports the driving hub 30. A wind-up driver mounted on the housing is coupled to the windup hub 30. The drive includes a disc 42 having manual drive facilities such as telephone style dialing finger holes or, in the preferred embodiment illustrated herein, a hand-grippable crank handle 44. The driver 42 is mounted on a shaft 46 (see FIG. 4) connected to wind-up hub 30. A pair of friction discs 43 are interposed in the drive train between the driver 42 and the hub 30 to prevent overwinding of the spring 14 and damage to the gear train 24 of the vehicle.

The vehicle gear train 24 includes a main driver gear 50 which is coaxially coupled to shaft 22 and engages a pinion 52 on a swing-shaft 54. The shaft 54 is movably mounted to the frame 13 of the toy vehicle by means of shaft-receiving slots such as 58 formed in the vehicle frame 13. Slots 58 define the limits and direction of movement of swing shaft 54 so that a swing gear 60, connected to shaft 54, may be selectively brought into contact with a pinion 62 coaxially coupled to a crown gear 64. The crown gear 64 in turn engages an axle pinion 66 mounted on vehicle drive axle 26.

The swing shaft 54 is so located that, during wind-up of spring 14 in the direction of arrow 67, a disengaging force is exerted on swing shaft 54 so that gear 60 is thus swung away from pinion 62. In this manner spring wind-up may be obtained without simultaneously rotating the vehicle drive axle 26. This permits the toy vehicle to remain stationary, resting its wheels against the platform 72, during the wind-up operation. Reverse rotation of gear 50 drives the swing gear 60 back into engagement with pinion 62.

A stop gear 68 is operatively coupled with a pinion 69 on shaft 22, and is provided with an interference segment 70. The stop gear 68 serves to limit the range of the vehicle by virtue of the binding effect that the interference segment 70 has on the gear train 24. Thus during vehicle travel when the spring 14 unwinds from output drum 18 the interference segment interrupts the spring drive 12 by engagement with larger pinion tooth 69a. Also, during spring wind-up, when the interference segment has been rotated into contact with pinion tooth 690, further winding is prevented. This bars overwinding of the drive spring 14.

FIGS. 3 through 6 shows a vehicle launch mechanism 100 which incorporates the described wind-up mechanism in a housing 138 sized to receive a toy vehicle on a pivotable platform 172. (Specific elements 138 and 172 in FIGS. 3-6 correspond to the more generalized elements 38 and 72 respectively of FIG. 1.) The driving hub 30 is shown protruding through an aperture 74 in platform 172. A vehicle positioning stanchion 76 is shown protruding through a slot 78 in platform 172. The stanchion 76 engages the rear end of the vehicle being wound so as to establish a precise position therefor, in which the vehicle is so located that the hubs 28 and 30 are in axial alignment to achieve winding engagement.

The platform 172 pivots about a horizontal axis 80 defined by pivot pins 81 affixed to the platform 172 and journaled on the housing 138. The platform is longitudinally sized so that its front end 82 may be pivoted to seat against the surface 84 on which the toy vehicle launch mechanism 100 is located. Surface 84 may be a floor, for example, or any other extended running surface for a toy vehicle. The platform 172 is conveniently pivoted down into launching attitude by applying pressure on a side tab 86 provided therefor, until the front end 82 comes to rest upon surface 84 as shown in FIG. 6. The toy vehicle 11 (seen in phantom in FIG. 6) is then automatically released from both the driving hub 30 and stanchion 76, and rushes down onto the surface 84 under the impetus of its spring motor.

An advantageous feature of the described wind-up clutch apparatus resides in the rapidity and ease with which the clutch hubs may be engaged and disengaged. When the combination winder-launcher device 100 of FIGS. 3-6 is used, for example, the vehicle is first placed over the hub 30, with its own hub 28 in axial alignment therewith, using stanchion 76 as a positioning guide. Such placement causes axial interpenetration of the hub teeth 34-34. Moreover, if the teeth 34-34 happen not to be circumferentially interspersed initially, and tooth-on-tooth engagement results, the gently sloping non-re-entrant tooth surfaces 34a (FIG. 2) of each hub will help cam the teeth of the cooperating hubs angularly into circumferentially interspersed relationship, thus facilitating axial interpenetration. The user then picks up the launcher-winder device 100, to gain access to the drive crank 44 therebelow. As soon as slight winding torque is applied to the crank, the driving hub rotates the points of its teeth 34 into angularly interpenetrating relationship with the reentrant recesses 36 of the driven hub teeth 34, thus completing the driving engagement between the hubs 28 and 30.

Once this is accomplished, the re-entrant slopes alpha of teeth 34-34 cooperate to produce a downward retaining force on the vehicle 11 which keeps it clamped securely to the platform 172. Thus there is no worry about the vehicle becoming disengaged from the winder 100, or possibly falling ofi if the winder is tilted to provide easier access to crank 44. Nor is there any need for hand pressure on the toy vehicle 11 to keep it in operative engagement with the winder. The user can devot one hand to holding up the winder so as to make the crank 44 accessible, and can use the other hand to turn the crank, while the vehicle 11 remains in place by itself. It will be appreciated that, for use with a winder mechanism of this type, in which the vehicle wheels 27 etc. are retained tightly against the platform 72 or 172 during winding, it is essential that the vehicle 11 have the feature described above whereby the drive wheels 27 are disengaged from the drive train during winding.

The vertical retention feature just described also serves to increase the security of the winding-forcetransmitting engagement between the hubs 28 and 30. Thus the user can wind as vigorously as he likes, without danger of disengagement. Indeed, the greater the winding torque exerted, the greater the retaining force component becomes.

Nevertheless, release of the hubs 28 and 30 is simple. When winding operation is complete, the user places the winder-launcher 100 down upon the floor or other running surface 84 for launching, with the vehicle 11 still adhering to the driving hub 30 of the winder by virtue of the re-entrant tooth engagement therebetween. But as soon as the user begins to pivot the platform 172 to the launching position of FIG. 6, the resulting upward pressure on the vehicle 11 causes the cooperating re-entrant surfaces 37 to react against each other in such a way that the hubs 28 and 30 are cammed to rotate them out of angularly interpenetrating relationship. (The tooth surfaces 37 achieve this in spite of the fact that the now fully wound spring 14 tends to drive the hub 28 of vehicle 11 in the tooth-engaging direction.) As the angular interpenetration of the teeth 34 34' decreases, axial withdrawal of the hubs 28 and 30 is permitted and the launching platform 172 continues to incline. Thus, in the act of launching the vehicle 11, the hubs 28 and 30 are automatically disengaged without the need for any special effort toward that end by the user. As soon as hub disengagement is complete, the vehicle 11 begins to be impelled by the wound spring 14, and then runs down the inclined launch platform and across the floor 84.

It will be appreciated that the expedient of placing the vehicle positioning stanchion 76 on the housing 138, so that the launching platform 172 rotates relative to the stanchion as the platform inclines to the launching position of FIG. 6, coupled with the fact that the stanchion is located to the rear of platform pivot pins 81. causes the rear end of the vehicle 11 to pull away from the stanchion as a result of the pivoting movement which the vehicle shares with the launching platform.

This prevents binding of the vehicle 1 1 against the stanchion 76, which would otherwise interfere with the launching operation.

The rapidity and ease of hub engagement and disengagement renders this wind-up mechanism particularly suitable in connection with a toy vehicle racing game as described and claimed in a copending patent application Ser. No. 126,818 entitled Toy Vehicle Racing Game filed by Julius Cooper, Burt Ensmann, Edwin Nielsen and Vincent Carella on the same date as this application and assigned to the same assignee as this invention. As described therein, spring driven toy vehicles must have their springs quickly re-wound during the course of a competitive race, preferably by devices employing clutch hubs such as those described in this application. For competitive racing use, the winder hub 30 is best incorporated in an alternate wind-up mechanism 200 illustrated in FIGS. 7 and 8. This mechanism represents a pit stop device for use with the toy vehicle competitive racing game described in the aforementioned co'pending application. The mechanism 200 has a housing 238 with a surface 272 (corresponding to elements 38 and 72 respectively of FIG. 1) for supporting the toy vehicle 11 of the preceding figures, the driven hub 28 of which is engaged by a driving hub 30 in the manner desribed with respect to FIGS. 1 and 2. Here, however, the hub 30, as shown in FIG. 7, is part of an alternate wind-up mechanism 210, and is coaxially connected to the drive pinion 96 thereof. The drive pinion 96 is engaged by a swing gear 98 which is mounted on a swing shaft 101. The swing shaft is mounted for movement in a slot 102 formed in a housing 92. An arcuately reciprocable drive lever 104 is mounted to housing 92 for pivotal movement about a shaft 106 between limits indicated by positions'lllS and 115'. A slot 108 in housing 92 enables the lever to protrude from the housing 92 for accessibility of a cylindrical handle 117 at the outer end thereof. The slot is also wide enough to permit reciprocation of lever 104 between its limit positions 115 115'. The lever is provided with a gear segment 110 which engages a pinion 112 mounted on swing shaft 101.

In the operation of the pit stop winding mechanism 200, the latter remains flat on the floor, and only the vehicle 1 I is moved, for the fastest possible winding operation. The vehicle is placed over the hub 30, using a fixed surface 276, corresponding to the stanchion 76 of launcher 100, as a vehicle positioning guide. The hubs 28 and 30 mesh axially as the vehicle is placed in position, and then mesh angularly as winding torque is applied, all as described in connection with launcher 100. The lever 104 is operated from the side of mechanism 200 instead of from underneath, so as to avoid the need for picking up the launcher and thus hasten the pit stop" winding operation. Yet here again, vertical retention of the vehicle 11 occurs during winding as a result of the interaction between the re-entrant surfaces 37 of hubs and 30, and is effective to maintain engagement therebetween, especially during vigorous winding, when disengagement might otherwise be a problem. During the time that the vehicle 1 l is thus retained tightly against the surface 272 by the vertical component of winding torque, the rear wheels 27 thereof are disconnected from the drive train as described above.

Rotation of the lever 104 in the direction of arrow 1 14 causes the swing gear 98 to move into engagement with the drive pinion 96 and rotate the drive hub 30. A

clockwise return movement of the lever 104 is accompanied by a disengaging movement of the swing gear 98 whereby it is moved away from the pinion 96. In this manner, repeated arcuate movements of the lever 104 back and forth between positions 115 and 115' provides a desired plurality of consecutive one-way rotations of the driving hub 30 to wind the toy vehicle spring 14 (FIG. 1). After winding, manual lifting of the vehicle causes a reaction between re-entrant surfaces 37 to produce simple and effortless angular and axial disengagement of hubs 28 and 30, as described above, with no special attention required.

A pair of friction discs 1 16 are operatively interposed between they drive pinion 96 and the drive hub 30. Thus, after the vehicle spring 14 (see FIG. 1) has been wound to the point where the interference segment has moved into contact with pinion tooth 69a, further actuation of lever 104 results in slippage of the friction discs 116.

Having thus described a wind-up mechanism for a spring driven toy, its advantages may now be appreciated. The axially extending teeth on the clutch hubs engage and disengage with the utmost speed and ease, and without the need for any attention specifically directed thereto. The vertical toy retention feature is useful in precluding disengagement despite vigorous winding, and is particularly advantageous in connection with the combination launcher and wind-up mechanism. In the latter mechanism, the hubs engage one another through an opening in the launching ramp to maintain the vehicle in a horizontal position until the spring has been wound, and then the ramp is tilted for launching, while the hubs disengage automatically.

Since the foregoing description and drawings are merely illustrative, the scope of protection of the invention has been more broadly stated in the following claims; and these should be liberally interpretated so as to obtain the benefit of all equivalents to which the invention is fairly entitled.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

l. The combination of: a toy having a spring drive comprising a spring, a driven hub mounted on the toy for rotation about an axis and operatively coupled to said spring to wind the spring upon rotation of the driven hub in a first direction, said driven hub being provided with extending teeth concentrically arranged about the driven hub axis of rotation; and a wind-up mechanism including a housing and a driving hub mounted for rotation on the housing, said driving hub being provided with extending teeth concentrically arranged about the axis of rotation of the driving hub, the teeth on each of said hubs being located on an axial end of the respective hub for axial engagement with the teeth of the other hub upon placing the toy upon the housing with the driving and driven hubs axially aligned, said teeth on each of said hubs extending axially and being shaped to slant in mutually complementary circumferential directions to form re-entrant capturing recesses for receiving the teeth of the other hub whereby to provide simultaneously both positive angular engagement between hubs and axial retention of the toy to the wind-up mechanism, and means for rotating said driving hub in a direction to wind the spring.

2. A wind-up mechanism for a spring-driven toy vehicle comprising:

a housing adapted to rest on a support surface for receiving the toy vehicle;

a toy vehicle launching platform pivotally supported by the housing, said launching platform being arranged to form an inclined ramp the lower end of which rests on the support surface when the ramp is pivoted to a launch position;

and means operatively extending through the platform for releasably engaging and winding the spring-driven toy vehicle when said vehicle is located on the platform.

3. The wind-up mechanism as in claim 2 wherein the means for winding the spring includes a drive hub rotatably mounted on the housing and extending upwardly through an aperture in the platform when said platform is pivoted out of said launch position to a substantially horizontal winding position, said aperture being located on the side of said platform which moves upwardly about the pivot axis thereof when pivoted from said winding position to said launching position, said hub being provided with teeth oriented to releasably engage the spring-driven vehicle for wind-up thereof when said ramp is in said winding position, and to release said vehicle as it moves upwardly in response to movement of said platform to said launching position.

4. The wind-up mechanism as in claim 3 wherein said vehicle comprises a driven hub provided with teeth engaging said teeth of said driving hub, and all of said hub teeth are releasably vertically interlocking to retain the toy vehicle vertically on the platform in response to winding torque.

5. The wind-up mechanism as in claim 4 wherein the I ing said spring drive from said drive wheels in response to winding torque exerted on said driven hub when rotation of said drive wheels is restrained, and said windup mechanism includes means for engaging said vehicle drive wheels when said hubs are in winding engagement so that said axial retention effect restrains rotation of said vehicle drive wheels by friction against said engaging means, and said drive wheels are then disconnected from said output drum.

8. The combination of claim 7 wherein said drive train disconnecting means includes first gear means connected to said spring drive, second gear means connected to said vehicle drive wheels, swing gear means connecting said first and second gear means for motive power transmission to said drive wheels, a swing shaft mounting said swing gear means, and a vehicle frame including slot means elongated to mount said swing shaft for movement in a direction to disconnect said first and second gear means in response to winding torque applied to said first gear means when said vehicle drive wheels are restrained to prevent said winding torque from rotating said second gear means.

9. The combination of claim 7 wherein said slot means is substantially concentric with said first gear means whereby said swing gear means always remains meshed with said first gear means.

10. A wind-up mechanism for a spring-driven toy vehicle, said mechanism comprising:

a housing; a toy vehicle supporting surface on said housing to receive the toy vehicle in a predetermined position;

rotatable means supported by said housing and extending through said housing for releasably engaging and winding the spring-driven toy vehicle when said vehicle is on said housing and in said predetermined position;

a winding handle; and

slip-type clutch means connecting said handle to said rotatable means to prevent overwinding of the spring-driven toy vehicle.

11. The wind-up mechanism as in claim 10 in which said clutch means comprises:

a first friction disc attached to said handle to be rotated thereby; and

a second friction disc attached to said rotatable means to drive the same and frictionally engaging said first friction disc to be rotated thereby.

12. The wind-up mechanism as in claim 11 in which said rotatable means comprises a shaft, said first friction disc is coaxial with said shaft, said winding handle is pivotally mounted on said shaft, and said second friction disc is also pivotally mounted on said shaft and attached to said handle to be rotated thereby.

13. The wind-up mechanism as in claim 11 comprising, in addition:

gear means connecting said winding handle to said second friction disc.

14. The wind-up mechanism as in claim 10 comprising, in addition, a second shaft mounted on said housing, and said winding handle is pivotally mounted on said second shaft, and said gear means comprises a gear segment mounted on said second shaft and attached to said handle and a driven gear rotatably mounted on said first-named shaft and connected to said second friction disc.

15. The wind-up mechanism as in claim 14 comprising, in addition, intermediate gear means connecting said gear segment to said driven gear, said handle extendig from said housing and being pivotally movable in a limited arc.

16. The wind-up mechanism as in claim 15 in which said second shaft is substantially parallel to said firstnamed shaft and said handle extends through a slot in one side of said housing.

i t l I 

1. The combination of: a toy having a spring drive comprising a spring, a driven hub mounted on the toy for rotation about an axis and operatively coupled to said spring to wind the spring upon rotation of the driven hub in a first direction, said driven hub being provided with extending teeth concentrically arranged about the driven hub axis of rotation; and a wind-up mechanism including a housing and a driving hub mounted for rotation on the housing, said driving hub being provided with extending teeth concentrically arranged about the axis of rotation of the driving hub, the teeth on each of said hubs being located on an axial end of the respective hub for axial engagement with the teeth of the other hub upon placing the toy upon the housing with the driving and driven hubs axially aligned, said teeth on each of said hubs extending axially and being shaped to slant in mutually complementary circumferential directions to form re-entrant capturing recesses for receiving the teeth of the other hub whereby to provide simultaneously both positive angular engagement between hubs and axial retention of the toy to the wind-up mechanism, and means for rotating said driving hub in a direction to wind the spring.
 2. A wind-up mechanism for a spring-driven toy vehicle comprising: a housing adapted to rest on a support surface for receiving the toy vehicle; a toy vehicle launching platform pivotally supported by the housing, said launching platform being arranged to form an inclined ramp the lower end of which rests on the support surface when the ramp is pivoted to a launch position; and means operatively extending through the platform for releasably engaging and winding the spring-driven toy vehicle when said vehicle is located on the platform.
 3. The wind-up mechanism as in claim 2 wherein the means for winding the spring includes a drive hub rotatably mounted on the housing and extending upwardly through an aperture in the platform when said platform is pivoted out of said launch position to a substantially horizontal winding position, said aperture being located on the side of said platform which moves upwardly about the pivot axis thereof when pivoted from said winding position to said launching position, said hub being provided with teeth oriented to releasably engage the spring-driven vehicle for wind-up thereof when said ramp is in said winding position, and to release said vehicle as it moves upwardly in response to movement of said platform to said launching position.
 4. The wind-up mechanism as in claim 3 wherein said vehicle comprises a driven hub provided with teeth engaging said teeth of said driving hub, and all of said hub teeth are releasably vertically interlocking to retain the toy vehicle vertically on the platform in response to winding torque.
 5. The wind-up mechanism as in claim 4 wherein the housing is further provided with a vehicle positioning stanchion extending upwardly through an aperture in the platform to position a toy vehicle located on said platform.
 6. The wind-up mechanism as in claim 2 and further including a slippable drive connection operatively associated with said hub to prevent over-winding of the spring driven toy vehicle.
 7. The combination of claim 4 wherein said toy is a vehicle having drive wheels and a drive train for connecting said spring drive to apply motive power to said drive wheels and incorporating means for disconnectIng said spring drive from said drive wheels in response to winding torque exerted on said driven hub when rotation of said drive wheels is restrained, and said wind-up mechanism includes means for engaging said vehicle drive wheels when said hubs are in winding engagement so that said axial retention effect restrains rotation of said vehicle drive wheels by friction against said engaging means, and said drive wheels are then disconnected from said output drum.
 8. The combination of claim 7 wherein said drive train disconnecting means includes first gear means connected to said spring drive, second gear means connected to said vehicle drive wheels, swing gear means connecting said first and second gear means for motive power transmission to said drive wheels, a swing shaft mounting said swing gear means, and a vehicle frame including slot means elongated to mount said swing shaft for movement in a direction to disconnect said first and second gear means in response to winding torque applied to said first gear means when said vehicle drive wheels are restrained to prevent said winding torque from rotating said second gear means.
 9. The combination of claim 7 wherein said slot means is substantially concentric with said first gear means whereby said swing gear means always remains meshed with said first gear means.
 10. A wind-up mechanism for a spring-driven toy vehicle, said mechanism comprising: a housing; a toy vehicle supporting surface on said housing to receive the toy vehicle in a predetermined position; rotatable means supported by said housing and extending through said housing for releasably engaging and winding the spring-driven toy vehicle when said vehicle is on said housing and in said predetermined position; a winding handle; and slip-type clutch means connecting said handle to said rotatable means to prevent overwinding of the spring-driven toy vehicle.
 11. The wind-up mechanism as in claim 10 in which said clutch means comprises: a first friction disc attached to said handle to be rotated thereby; and a second friction disc attached to said rotatable means to drive the same and frictionally engaging said first friction disc to be rotated thereby.
 12. The wind-up mechanism as in claim 11 in which said rotatable means comprises a shaft, said first friction disc is coaxial with said shaft, said winding handle is pivotally mounted on said shaft, and said second friction disc is also pivotally mounted on said shaft and attached to said handle to be rotated thereby.
 13. The wind-up mechanism as in claim 11 comprising, in addition: gear means connecting said winding handle to said second friction disc.
 14. The wind-up mechanism as in claim 10 comprising, in addition, a second shaft mounted on said housing, and said winding handle is pivotally mounted on said second shaft, and said gear means comprises a gear segment mounted on said second shaft and attached to said handle and a driven gear rotatably mounted on said first-named shaft and connected to said second friction disc.
 15. The wind-up mechanism as in claim 14 comprising, in addition, intermediate gear means connecting said gear segment to said driven gear, said handle extendig from said housing and being pivotally movable in a limited arc.
 16. The wind-up mechanism as in claim 15 in which said second shaft is substantially parallel to said first-named shaft and said handle extends through a slot in one side of said housing. 